How much faster? TT

Ptrckzq

I imagine this has probably been answered somewhere before (my apologies) but in my extensive googling I dont seem to have had much luck.

So, I have an important TT coming up. Its about 13km, almost completely flat save a small hill for 1km at only 3% or so and only one real corner.
And I have the opportunity to borrow a disc wheel and 80/90mm front, TT helmet (Kask Bambino pro), and could also get a new skinsuit(say NoPinz Bioracer).
My question is, compared to me on my TT bike in a very well fitted jersey&shorts with a road helmet and standard 45mm rims, just how much faster would I be? Is it worth the effort for a TT so short?

Also, my power will be somewhere around 340W for the TT, and my TT position is quite good if it matters.

Many thanks in advance!

trivial_poursuivant

Do you know which way the wind will be blowing and how strong?


And I don’t mean this in a pedantic way. You could have a disc and ultra deep section front and they could work against you. Just going a+b+c = faster doesn’t work. There is a lot more to it than that.

Bambino isn’t the fastest helmet. It just gives you a bit a flexibility in your position which ultimately that helmet may not suite.

Matthewfalle

Why is it important out of interest?

Ptrckzq

Its the first stage of an upcoming 3 day tour and I'd rather not start it by losing time!
Also there shouldnt be much wind at all.
Mainly though, what I'm getting at is, will it make much of a difference, if at all, over a short TT like this? Say would I be able to shave off 30sec to a minute? More? Less? Thats all I'm really after

okgo

10 miles probs about 90 seconds diff.

imposter2.0

Ptrckzq wrote:

Its the first stage of an upcoming 3 day tour and I'd rather not start it by losing time!
Also there shouldnt be much wind at all.
Mainly though, what I'm getting at is, will it make much of a difference, if at all, over a short TT like this? Say would I be able to shave off 30sec to a minute? More? Less? Thats all I'm really after

Look at it this way - it's probably not going to make you slower. If you have access to the kit, then you might as well use it. As you say, if it's a prologue, then every second will help..

cougie

It's impossible to say but why wouldn't you ?

Ptrckzq

cougie wrote:

It's impossible to say but why wouldn't you ?

Ive never ridden a disc or anything deeper than 40/50mm rim nor used a TT helmet before and probably wouldnt get much practice with them, max 2-3 rides, before the race

cougie

A helmet is a helmet. Just make sure it fits properly.

Disc wheel isn't that different from normal wheel.
Maybe think twice if it's really windy.

okgo

1 - a disc wheel is quite a bit faster than a normal wheel, not much faster than a deep section wheel, though.
2 - a disc wheel in the wind is not your concern, a 90mm front wheel might be, the rear makes little odds

trivial_poursuivant

cougie wrote:

A helmet is a helmet. Just make sure it fits properly.

An aero helmet is probably more beneficial than a disc wheel. The rider causes more drag than the bike and with your head being quite a prominent part of your overall frontal area a more aero TT helmet will save you a lot over one full of vents.

Matthewfalle

How much faster is an aero helmet than say a normal vented one with the vents taped up?

trivial_poursuivant

Which aero helmet vs which taped up vented?

So many on the market it’s hard to say. But I would think something like a Giro Aerohead would save a fair few watts over say a Regular helmet vented or closed.

Matthewfalle

jus wondering if it was a good and cheap way of getting the benefits of an aero helmet (one of those with the cover on, not a full on TT lid) whilst using a normal lid that everyone has,

Do it properly neat and people probably won't even notice its tape.

trivial_poursuivant

Matthewfalle wrote:

jus wondering if it was a good and cheap way of getting the benefits of an aero helmet (one of those with the cover on, not a full on TT lid) whilst using a normal lid that everyone has,

Do it properly neat and people probably won't even notice its tape.

I have a Bontrager Ballista as my road helmet and a Giro Selector as my TT helmet. Even though the Ballista is quite a good aero helmet in itself the Giro with the deep tail section is a lot better. For my TT position anyway.

napoleond

If you have the opportunity of using that kit for free, definitely do it!! It may make 5 seconds difference, it might make 90.
If you lost a podium spot by a couple of seconds and hadn’t gone for it then what would you be telling yourself?

MiddleRinger

Plus a disc wheel just SOUNDS faster - and that's worth it!

Don't expect miracles of course. My back of a napkin maths (okay, complete mental maths guestimate) says you'll save roughly 20-30 seconds.

Nick Payne

Just remember - when using a disc wheel, if you can hear the noise it makes over the bumps, you're not going fast enough.

trivial_poursuivant

Nick Payne wrote:

Just remember - when using a disc wheel, if you can hear the noise it makes over the bumps, you're not going fast enough.

That shouldn’t be noticeable over the sounds of your heart trying to escape from your chest and the blood rushing in your ears.

burnthesheep

Are you on a team or are you doing this race alone without a team?

If you're on a team what is your role on the team? I'd assume with this question you are either doing the race alone OR you are the team's GC contender.

If it is a flat race, then yeah, I'd put a billion % effort into the TT. If you're the GC and the race has a chance to split the pack on a climb.........it may not be worth crashing in the TT.

Also, if you are on a team.........you would already know who is pretty much going to do what in the TT based on the course and their TT abilities.